"Is it an ethnicity? Is it a community? Is it a culture?" said Anna Aruntunyan, a journalist for Moscow News and contributor to USA TODAY. "It's all these things at once."

Some Cossacks say the people identifying themselves as Cossacks in Sochi are not truly Cossacks, Aruntunyan said.

"Some comments I've seen is that these Cossacks don't even know how to ride a horse," she said.

People identifying themselves as Cossacks today embrace a "racist, nationalist and anti-Semitic" worldview, said Ariel Cohen, a senior fellow at Heritage Foundation, who is a Russia specialist.

According to the state-run news agency Ria Novosti, the Cossacks are serving as volunteer security officials for the Olympics. More than 400 Cossacks arrived in Sochi in early January to help the police maintain order, the news agency said.

The Cossacks have a "semi-official" role in Russia and "sometimes carry out self-appointed vigilante police duties that are now becoming officially authorized in some parts of the country, including Moscow," according to Ria Novosti.

Their law enforcement role is not clearly defined and falls into a gray area.

"It's dangerous because it is not set in law and it is not regulated real well," Cohen said.

In December, Russian President Vladimir Putin said Cossacks could be more effective than police, but they still had to work within the confines of the law, according to RT, formerly known as Russia Today.